Pigment: The Colored Substance That Makes Paint Paint

In a cave at Twin Rivers, near Lusaka, Zambia, archaeologists found pigment and paint grinding equipment believed to be between 350,000 and 400,000 years old. The pigment was ochre, an iron oxide, and it was the first color of paint. Humans have been grinding colored minerals and mixing them with binders to make paint for longer than our species has existed in its modern form. Every painting ever made, from the caves at Lascaux to a canvas in a contemporary gallery, depends on the same basic ingredient: pigment. Without pigment, there is no color. Without color, there is no painting.

A pigment is a finely ground colored material, made from natural substances (animal, vegetable, or mineral) or synthetic chemical processes, that is used in paints, dyes, and inks. Pigments are nearly or completely insoluble in the medium they are mixed with. They remain as solid particles suspended in the binder, unlike dyes, which dissolve into solution. This distinction is fundamental: pigment particles hold their color and do not migrate once the binder has dried, while dyes can bleed and shift. The word comes from the Latin "pigmentum," derived from "pingere," meaning "to paint."

This entry covers the history of pigments from prehistoric ochre to modern synthetics, the difference between natural and synthetic pigments, how pigments are made and used, and why some pigments last for millennia while others fade in months.

What Is a Pigment?

Pigment is the ingredient that gives paint its hue. It is a colored, solid particle dispersed throughout the vehicle. Pigment holds its color and does not dissolve into the vehicle or migrate once the binder has dried. This is what distinguishes pigments from dyes. Dyes are colored substances that are soluble in the medium. In order for a dye to be used in paint, it has to be made into what is called a "lake pigment" by fixing it to an inert solid substrate, usually aluminum hydrate. This process converts the soluble dye into an insoluble pigment particle that can be mixed with a binder.

Pigments work by selectively absorbing certain wavelengths of light and reflecting others. The reflected wavelengths are what we perceive as color. A red pigment absorbs most of the blue and green wavelengths and reflects the red. The chemical structure that causes this selective absorption is called the chromophore. In organic pigments, the chromophore is typically a system of conjugated double bonds, where chemical bonds alternate between single and double bonds. This structure allows the molecule to absorb light in the visible range. In inorganic pigments, the color is often produced by the presence of specific metal ions in the crystal structure.

Pigment particles are not uniform. They vary in size, shape, and crystal structure, all of which affect the color and behavior of the paint. Smaller particles generally produce more transparent, more intensely colored paint. Larger particles produce more opaque, lighter paint. The particle size also affects how the pigment disperses in the binder and how it ages over time. The Blick Art Materials guide to paint explains: "Pigment is combined with the vehicle in a way that breaks up clusters and clumps so each particle is separately surrounded, in a process called dispersal."

History of Pigments

Prehistoric and Ancient Pigments

The earliest pigments were all natural minerals. Ochre, an iron oxide, was the first. Red ochre (anhydrous Fe2O3) and yellow ochre (hydrated Fe2O3) appear in Paleolithic and Neolithic cave paintings around the world. Charcoal, or carbon black, has been used as a black pigment since prehistoric times. White was provided by chalk (calcium carbonate) and kaolin clay.

The first known synthetic pigment was Egyptian blue, a calcium copper silicate (CaCuSi4O10), first attested on an alabaster bowl in Egypt dated to Naqada III, circa 3250 BC. Egyptian blue was made by heating a mixture of quartz sand, lime, a flux, and a copper source such as malachite. It became widespread by the 4th Dynasty and was the blue pigment of choice throughout Roman antiquity. Its use vanished during the Middle Ages and was only rediscovered in the context of excavations in Pompeii and Herculaneum.

Other early synthetic pigments include white lead (basic lead carbonate), vermilion (mercury sulfide, originally made by grinding natural cinnabar), verdigris (copper acetate), and lead-tin yellow. Vermilion was favored by old masters including Titian. From the 17th century onward, vermilion was also synthesized from its elements rather than being ground from natural cinnabar.

Lapis Lazuli and Ultramarine

The most prized pigment of the medieval and Renaissance periods was ultramarine, made from lapis lazuli mined in the mountains of Afghanistan. The stone was ground, washed, and processed to separate the blue mineral (lazurite) from the surrounding rock. The process was laborious and the pigment was more expensive than gold. Cennino Cennini, in his 15th-century craftsman's handbook, wrote that ultramarine "is a color noble, beautiful, and most perfect, beyond all other colors." Its use was reserved for the most important parts of a painting, typically the robes of the Virgin Mary. Because of the cost of lapis lazuli, substitutes were often sought. See our entry on ultramarine for the full history.

The Industrial Revolution and Synthetic Pigments

The Industrial Revolution transformed pigment production. Prussian blue, the oldest modern synthetic pigment, was discovered by accident in 1704 by a Berlin dye maker named Diesbach. By the early 19th century, synthetic and metallic blue pigments included French ultramarine, a synthetic form of lapis lazuli manufactured by treating aluminium silicate with sulfur. Various forms of cobalt blue and cerulean blue were also introduced. In the early 20th century, phthalo blue, a synthetic metallo-organic pigment, was prepared.

Cadmium pigments, first produced commercially in the 1840s, provided a range of yellows, oranges, and reds with exceptional brightness and opacity. They quickly became the standard for high-quality oil paint. See our entry on cadmium colors for details. The discovery of synthetic alizarin in 1868 replaced the natural madder root as the source of red lake pigments, making red paint cheaper and more consistent.

Indian yellow, a pigment once produced by collecting the urine of cattle fed only mango leaves, was used by Dutch and Flemish painters of the 17th and 18th centuries for its luminescent qualities. Since mango leaves are nutritionally inadequate for cattle, the practice was declared inhumane and banned in 1908. Modern Indian yellow is made from synthetic pigments. See our entry on Naples yellow and indigo for other historical pigments with complex origins.

Modern Pigments

The 20th century brought an explosion of synthetic organic pigments. Quinacridones, introduced in the 1950s, provide highly permanent reds, oranges, and magentas. Phthalocyanines, introduced in the 1930s, provide intense, permanent blues and greens. Dioxazine violet, pyrrole red, and benzimidazolone yellows are all products of 20th-century chemistry. These synthetic pigments are often more permanent, more consistent, and less toxic than their historical counterparts. The Princeton University Press book Pigments traces this history across cultures and time periods.

Natural vs. Synthetic Pigments

Natural pigments are derived from minerals, plants, or animals. They include ochre, umber, sienna (all iron oxides from specific regions), lapis lazuli, malachite, cinnabar, charcoal, bone black, cochineal (from insects), and indigo (from plants). Many natural pigments bear the name of the city or region where they were originally mined. Raw sienna and burnt sienna came from Siena, Italy. Raw umber and burnt umber came from Umbria. These place names persisted even after chemists created synthetic versions of the same colors.

Synthetic pigments are produced through chemical processes. They include all the pigments discovered since 1704, from Prussian blue to modern quinacridones. Synthetic pigments are more consistent than natural pigments, because their chemical composition is controlled. Natural pigments vary in color and properties depending on where they were mined and what impurities they contain. Synthetic pigments can be engineered for specific properties: particle size, transparency, lightfastness, and tinting strength.

Some pigments that were originally natural are now produced synthetically. Ultramarine, once ground from lapis lazuli, has been manufactured synthetically since 1828. Vermilion, once ground from cinnabar, has been synthesized from mercury and sulfur since the 17th century. The synthetic versions are chemically identical to the natural ones but are more consistent and less expensive.

Key Pigments and Their Properties

Some pigments have been so important to art history that they have their own glossary entries. Ultramarine, from lapis lazuli, was the most expensive pigment of the Renaissance. Lead white, used for centuries, is now largely replaced by titanium white and zinc white due to toxicity. Vermilion, from cinnabar, was the standard red for centuries. Cadmium pigments provide the brightest modern reds and yellows. Ochre is the oldest pigment still in use. Carbon black and bone black are the traditional blacks. Cochineal, a red lake from insects, was one of the most important organic pigments of the colonial era.

Pigment Stability and Lightfastness

Not all pigments are permanent. Some pigments fade over time when exposed to light, a property called fugacity. Pigments that fade are called fugitive colors. Organic pigments, which contain conjugated double bonds in their chromophore, are generally more prone to fading than inorganic pigments, because the double bonds are sensitive to light, heat, and oxygen. When these bonds break, the molecule loses its ability to absorb specific wavelengths, and the color disappears. See our entry on fugitive color for a detailed explanation.

Inorganic pigments, such as iron oxides, cadmiums, and ultramarine, are generally very stable. The same ochre that was painted on cave walls 40,000 years ago is still the same color today. This is why many ancient paintings retain their earth tones while their blues, reds, and purples have faded: the earth tones are inorganic iron oxides, while the blues and reds were often organic pigments derived from plants or insects.

Pigment stability is measured using the International Standards Organization (ISO) Blue Wool scale, which rates lightfastness from 1 (very fugitive) to 8 (extremely permanent). Most professional-grade artist paints now include lightfastness ratings on the tube. For more on this topic, see our entries on fugitive color and the broader concept of color in art.

Related Terms

Pigment is one of the two essential components of paint, the other being the binder. The liquid that carries both is the vehicle. Pigments are applied to a support that has been prepared with a ground. For specific pigments, see our entries on ultramarine, lead white, titanium white, cadmium colors, ochre, vermilion, carbon black, and cochineal. For more on how pigments behave in paint, read our post on oil painting techniques.

See Pigments in Person

The best place to see the history of pigments is in any museum with a broad collection. The cave paintings at Lascaux (or their replica at Lascaux IV) show ochre, charcoal, and iron oxide in their original form, still vibrant after 17,000 years. The National Gallery in London has Renaissance paintings where ultramarine blues remain intense alongside areas where organic red lakes have faded to nothing. The Rijksmuseum in Amsterdam has Rembrandt's paintings, where the earth pigments and lead whites are as stable as the day they were mixed, while some of his red lakes have shifted or disappeared.

For a focused study of pigment history, the Harvard Art Museums' Forbes Pigment Collection, housed in the Straus Center for Conservation and Technical Studies, contains over 3,000 pigment samples, including rare historical pigments like Indian yellow, mummy brown, and dragon's blood. The collection is used for identifying pigments in historical paintings.

For more on the materials of painting, read our entries on binder and vehicle, or explore our post on oil painting techniques to see how different pigments behave in oil paint.